Like everyone else, I'm working on Screen Space Ambient Occlusion. Initially, I implemented Crytek's version of SSAO which is listed in ShaderX7. However, there's a lightening near the edges and it just bugs me. So, I went on experimenting Starcraft 2 SSAO technique by considering normal + depth.

I think the result looks better although it is very noisy. When the scene is moving, the AO is shimmering which is not good. In addition, since I render the AO in a half resolution buffer, I got some problem near the edge when combining AO with the real scene. Anyway, check out my current SSAO implementation: